enable case-insensitive tab completion for files and folders

sort the completions before validation as the order isn't guaranteed
[feature]
need to explicitly have enumoptions not skip hidden/system files to retain existing behavior
PowerShell · iSazonov · Oct 28, 2018 · iSazonov · Oct 28, 2018 · SteveL-MSFT
diff --git a/...m.Management.Automation/engine/CommandCompletion/CompletionCompleters.cs b/...m.Management.Automation/engine/CommandCompletion/CompletionCompleters.cs
diff --git a/src/System.Management.Automation/namespaces/FileSystemProvider.cs b/src/System.Management.Automation/namespaces/FileSystemProvider.cs
diff --git a/test/powershell/Host/TabCompletion/TabCompletion.Tests.ps1 b/test/powershell/Host/TabCompletion/TabCompletion.Tests.ps1
diff --git a/test/powershell/Host/TabCompletion/TabCompletion.Tests.ps1 b/test/powershell/Host/TabCompletion/TabCompletion.Tests.ps1
+        }
+
+        It "Test case insensitive folder path" -Skip:(!$IsLinux) {
+            $testDirs = "AA", "Aa", "aa"
diff --git a/...m.Management.Automation/engine/CommandCompletion/CompletionCompleters.cs b/...m.Management.Automation/engine/CommandCompletion/CompletionCompleters.cs
diff --git a/test/powershell/Host/TabCompletion/TabCompletion.Tests.ps1 b/test/powershell/Host/TabCompletion/TabCompletion.Tests.ps1
diff --git a/...m.Management.Automation/engine/CommandCompletion/CompletionCompleters.cs b/...m.Management.Automation/engine/CommandCompletion/CompletionCompleters.cs
diff --git a/test/powershell/Host/TabCompletion/TabCompletion.Tests.ps1 b/test/powershell/Host/TabCompletion/TabCompletion.Tests.ps1